diff --git a/2019/duble/.gitignore b/2019/duble/.gitignore
index b4c82d6c7..2b8115603 100644
--- a/2019/duble/.gitignore
+++ b/2019/duble/.gitignore
@@ -6,3 +6,4 @@ Linux
 Linux.alt
 prog
 prog.alt
+.[A-Z][A-Z]*